Bloomberg News reports dozens of trading accounts of Saudis accused of corruption have been blocked.

Trading accounts of Saudis accused of corruption have been frozen, according to a news report, as fears grow among the kingdom's wealthy that offshore bank accounts could also be locked.

Dozens of trading accounts were blocked at the request of the Capital Market Authority, the Saudi government's financial regulatory body, Bloomberg News reported on Thursday citing three anonymous sources with knowledge of the situation.

The move follows the crackdown that began on November 4 by Crown Prince Mohammed bin Salman who has arrested more than 200 Saudi elite - including 11 princes and prominent corporate leaders - who are accused of corruption.

The Bloomberg report comes after many private bank accounts of those held were recently seized in Saudi Arabia. Observers say it is just a matter of time before overseas accounts are also targeted.

"According to domestic banking sources, more than 2,000 bank accounts have already been frozen," said Enzo Caputo from the Switzerland-based Caputo & Partners law firm. "The fishing expedition will be extended to Swiss banks very soon."

Caputo noted about 55 percent of the Saudi elite's wealth is kept in foreign tax havens. Concerned Saudi investors have been in contact with his firm and expressed fears Swiss banking authorities will freeze their accounts at the request of the Saudi government, he said.

"They are at an extremely high risk to be frozen," Caputo said in an email.

Sheikh Saud Al Mojeb, the Saudi attorney general, has said corruption "uncovered is very large".

"Based on our investigations over the past three years, we estimate that at least $100bn has been misused through systematic corruption and embezzlement over several decades," Mojeb said.

More than 200 people have been called in for questioning and seven have been released without charge, according to the attorney-general.

Some analysts have questioned whether the mass arrests are truly related to corruption, or if the move is a purge by the crown prince to neutralise rivals and seize their vast assets.